Test your PAC file - which line fires for which URL?
Paste your PAC file or upload it, enter one or more test URLs. You'll instantly see the result (DIRECT/PROXY) and which return line in the source produced it.
PAC file
Paste the text or choose a file.
Result
Hints
Build and test it here.
CentaurNexus supports controlled individual changes in approved Zscaler workflows – with tenant policy, audit and read-back.
View product demoFrequently asked questions
It runs the FindProxyForURL function of your PAC file against one or more test URLs and shows the result (DIRECT or PROXY host:port) plus which return line in the source produced it.
No. Evaluation runs entirely in the browser in an isolated sandbox (sandboxed iframe without network or parent-window access); there is no server round trip.
No, deliberately not. Real DNS resolution would require a network request and would contradict the promise that the PAC file never leaves your machine. Functions like dnsResolve or isInNet with hostnames therefore return a documented empty value for hostnames instead of a fabricated answer - for IP addresses they work normally.
The complete standard Netscape PAC API: isPlainHostName, dnsDomainIs, localHostOrDomainIs, isInNet, shExpMatch, dnsDomainLevels, weekdayRange, dateRange, timeRange, plus the IPv6 extensions isInNetEx/isResolvableEx/myIpAddressEx. Date/time and the simulated local IP can be set for reproducible tests.
DIRECT means the browser should connect straight to the destination without going through a proxy. PROXY host:port means the request should go through that proxy server first; when a PAC file lists several proxies separated by semicolons, the browser tries them in order and falls back to the next one if the first fails.
Yes. Add as many test URL rows as you need with the '+ another URL' button; each one is evaluated separately and gets its own result and matching line.
The tester catches it and reports a syntax error message instead of a result, so you know the file needs fixing before it can be evaluated against any URL.
Both. Alongside the DIRECT/PROXY result for each URL, the tester runs a set of hints that flag issues in the PAC source itself, shown separately as errors, warnings or informational notes.
Yes. The simulated date and time field lets you set the value used for functions like weekdayRange, dateRange and timeRange, so you can reproduce time-based routing logic without waiting for the actual day or hour to arrive.